Regarding Offline installation of VLC, Amarok
 

I don't have an internet connection. is there any way to install vlc and enabling mp3 support in amarok without going through yum.

You will need at least one system that's online to do anything like that. Google "yum offline" for a list of methods.
Some packages can be installed via .rpm files. but you will need all the dependencies and that could be a major headache for a complex package like vlc.
Look at the vlc how to for installing vlc.
.rpm repositories are also available. I've used pbone repository before to download .rpm files. (but don't take that as an endorsement of that site.)